I also have Nautilus 804. Marantz has good bass weight, I found the Rega Planet to be bass light on ProAc 2.5 / Dynaudio 3.0. Cary CD 303 also good in the bass but the sonic improvements were virtually inaudible to me. Since you know you want to upgrade CDP this will at least give ou the full 40Hz (-2db) that N804 can do. I use single (not Bi-wire) Home Depot 12 ga and found no loss in the bass over DH Labs Q-10 external biwire.
Try puttingthe N804 more in a corner. Against the wall won't help since they are front ported. You will loose bass definition though.
Try puttingthe N804 more in a corner. Against the wall won't help since they are front ported. You will loose bass definition though.